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Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Crystal structure, hydrogen bonds and thermal transformations of superprotonic conductor Cs6(SO4)3(H3PO4)4
Irina Makarova1, Elena Selezneva1, Laura Canadillas-Delgado2
1Shubnikov Institute of Crystallography of Federal Scientific Research Centre `Crystallography and Photonics' of Russian Academy of Sciences, Leninsky pr. 59, Moscow 119333, Russian Federation.
Abstract:
Crystals of Cs6(SO4)3(H3PO4)4 belong to the family of alkali metal acid salts that show a high protonic conductivity at relatively low temperatures. Such properties make superprotonic crystals an excellent choice for the study of the influence of the hydrogen subsystem on the physicochemical properties and promising materials for energy-efficient technologies. Single crystals of Cs6(SO4)3(H3PO4)4 were studied by neutron diffraction methods, optical polarization microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Neutron diffraction studies made it possible to determine the positions of all the atoms with high accuracy, including the H atom on a hydrogen bond characterized by a single-minimum potential, to confirm the chemical composition of the Cs6(SO4)3(H3PO4)4 crystals and their cubic symmetry in low- and high-temperature phases, and to draw conclusions about the three-dimensional system of hydrogen bonds, which is fundamentally different in comparison with other superprotonic compounds. Based on the experimental data obtained, crystal transformations with temperature changes are reported, and the stability of the chemical composition is shown.
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